Follow the specs for AMPS. I go with Yuasa whenever possible with the max cold crank CCA possible. My '07 1100 is a cold weather princess. I'm talking grief at 50 degrees! I made a mistake once upon a time and got a gel cell that wa ssupposed to the the greatest thing since Lucas. The battery lasted almost a year...

Follow the specs for AMPS. I go with Yuasa whenever possible with the max cold crank CCA possible. My '07 1100 is a cold weather princess. I'm talking grief at 50 degrees! I made a mistake once upon a time and got a gel cell that wa ssupposed to the the greatest thing since Lucas. The battery lasted almost a year...

Agree 100%.

I buy YUASA exclusively and match the ampere hours.

When it's 15 degrees in my garage and I'm firing up all the bikes every two weeks during the winter, there is NO difference between one advertising a 210 CCA and one advertising a 230 CCA.

The specs on it are at MB12U - it's 160 CCA (I've always known that to mean "cold cranking amps" but I've never actually looked for a definition).

It's easily enough to start my car, so long as my car starts quickly - the car (1500cc) would crank at full speed but the battery wouldn't last long if the car took say a couple of minutes to start (not a problem once I fixed the automatic choke)

There is a "Capacity (10HR)" which is rated at 15, no idea what that is TBH. What I know is that it starts my Shadow without trouble (at least when she's in one piece, not in several dozen pieces scattered across a 20 mile radius!), and in the years I've had that battery I've not had a moments problem with it.

For example, you wouldn't want to use a super high output alternator on your car if it didn't come with one from the factory because it will tend to just slam the battery too fast, resulting in only quick 'surface charges' being given to the battery.

While the overall advice is good, I would like to question this.

Electronic components tend to only draw the current they wish, up to the upper limit of the supply. So a 12v12w light bulb will always 1amp if it has 1a or more available. If you put it on a supply that can give it a million amps it'll still draw only 1.

So I'd like to know what makes a battery different? (Knowing the science or theory behind something like this means that I can pass it on to others, whereas right now I'd be less inclined to).

One thing I have seen with a lot of people adding non-standard stuff to their vehicles is they're not always doing the job right, eg higher wattage bulbs that melt their housings, or fitting stuff that draws more power than the wiring loom can handle and so on. It would not surprise me if people changing alternators and so on can cause new issues or exacerbate old ones that may not even show up (eg failing insulation near the tail light that is fine under the lower power alternator, but can short under a higher power one)

Quote:

When it comes time to change the battery in my newest bike, I will use the same method I've used over the last 55 years of riding in all my bikes, and the wife's bikes, and my son's bikes, and my grandson's bikes.

So I'd like to know what makes a battery different? (Knowing the science or theory behind something like this means that I can pass it on to others, whereas right now I'd be less inclined to).

I am no expert on this topic but I'm assuming you're asking what makes a battery different than a light bulb. The major difference is that a light bulb is solely a load and a battery is both a supply and a load. It's a supply when it's discharging and it's a load when it's being charged. A battery with a higher capacity is going to discharge less; and in turn (because of it's slower discharge rate) will be less of a load when it's being recharged. A lower capacity battery is going to go through more and prolonged cycles of discharging/charging causing a shorter service life of the battery as well as overburdening the charging system on the vehicle.

Best advice in terms of battery capacity is to go with what the manufacturer recommends. And if you are going to stray from those recommendations, make sure the new battery's specs exceed those recommendations in terms of capacity.
Phil

Electronic components tend to only draw the current they wish, up to the upper limit of the supply. So a 12v12w light bulb will always 1amp if it has 1a or more available. If you put it on a supply that can give it a million amps it'll still draw only 1.

So I'd like to know what makes a battery different? (Knowing the science or theory behind something like this means that I can pass it on to others, whereas right now I'd be less inclined to).

One thing I have seen with a lot of people adding non-standard stuff to their vehicles is they're not always doing the job right, eg higher wattage bulbs that melt their housings, or fitting stuff that draws more power than the wiring loom can handle and so on. It would not surprise me if people changing alternators and so on can cause new issues or exacerbate old ones that may not even show up (eg failing insulation near the tail light that is fine under the lower power alternator, but can short under a higher power one)

That's what works best most of the time anyway

Phil's Load/Battery Supply comparison is how you want to think of it. He explained it very well.

The process starts the day you first buy the battery and charge it at a really low amp load so that the battery not only has the required 12.6 volts, but the capability to maintain close to that voltage as the amps are being pushed through the battery when the charging process is done.

It's one of the reasons I never let them add the acid to my batteries. The vendor usually wants to add the acid for you, give it a 'quick' charge (14 volts and lots of amps), and then have you out the door as soon as he's done. The battery will have all the volts it needs, but it will not be able to maintain those volts for very long once the amps start being pulled through it. In effect, the dealer is just giving you a 'surface charge'.

Lead acid batteries, if they are going to last a long long time need to be charged slowly. No matter if it's the day you bought it, or during it's life in the vehicle.

So that super high output alternator is going to be trying to do the same thing to your stock sized battery during it's life every time it enters the charging state.

Match the amp load requirements of the vehicle to both the battery and the alternator.

Does anyone know how much harm it does to your battery when you jump start it from a car? My last battery I had to jump it 4 times. I'm asking so I dont ruin my new AGM battery. I just hooked it up like a normal car jump.

The battery itself should generally be fine - with normal lead-acid batteries it's the low voltage that does the damage, jumping off a car (with the leads in parallel with the battery) should have little to no effect.

The issue you most need to worry about is your voltage regulator. Older bikes/bikes that don't have car-style alternators use a simple regulator that basically dumps extra volts out to earth. As it does so, it causes the regulator to heat up.

Car style alternators adjust themselves considerably to keep the voltage up. This means that if you're trying to jump start from a car with the car's engine running, you poor bike's regulator is trying to handle the car's power load, which is considerably more than what it is designed to to.

My normal practice is to hook the bike up and let the car put some charge into the bike's battery with the bike OFF, then turn the car off and try to start the bike a couple of times. If I feel I need to, I'll turn off the bike and start the car again.

As mentioned elsewhere, I've found (especially on cold days) a bit of hot water can help a lot to get things going. Of course, you could also look for chemical alternatives to assist, such as (IIRC) WD40, or various substances including my favourite, a product named "Start ya b'st'rd" (the B word is the term used for a child of un-married parents)

Last edited by KiwiRider; 11-25-2017 at 12:08 AM.
Reason: Couldn't name a product due to language restrictions

No it's not. An alt only puts out what is needed. At idle with a reasonably charged battery the output is pretty low. There is no danger. The only difference is using a running car the dead battery and starter see about 14, which is what you want the dead vehicle to see. .

I've killed regulators doing exactly that, and it only took a few seconds.

If the car is outputting a little higher v than that bike wants (therotically even .1v) the bike's regulator will try to dump that excess voltage to ground. As the car can put out more than the regulator can handle, it doesn't take long.

Bikes that have car-style alternators and a number of modern regulators aren't as likely to suffer damage from this, but the older Shadows can pop fairly quickly (the last one I killed was on a '85 500)

Your bike, your risk, but I'd always strongly recommend NOT having the car running when the bike is on.

First, I tapped a wire that is simply the "on" wire from the ignition. That runs to a relay's switching coil, so when the bike turns on it flips the coil for the relay.

I used a 30a relay, and a line from the battery goes to that then to a small terminal block. If you can find an insulated bus bar or similar you can use that as well. In my case I couldn't, and so I ran wire loops on one side of the terminal block to make it all connected. If I want to add a new device I just have to wire into the existing block.

Off that I have my voltage display/clock, some under-tank lights (controlled via a separate switch), power for my GPS and a 5V USB socket for phone chargers etc (not all connected atm)

The purpose of the relay is to remove the load from the switch contacts. Not really likely to be an issue, but it lessens the risk of things burning out. Also, I can easily add in a "voltage switch" circuit or other stuff (this is a circuit that would switch the extras off at IIRC 11.5V and back on at 13V - so if I was sitting at traffic lights my extra lights, heating, gadgets etc wouldn't drain things down on me (guess where I got the idea from... )

2nd pic shows the wire coming from the bottom from the battery (if the bike was intact atm) to the fuse, to the relay, and then to the terminal block. It also shows that while I am waiting for the rest of the engine stuff I better get out, get some rolls of wire, and tidy up the wiring! The other two relay wires are 1 to earth and 1 to a wire from the ignition switch as mentioned above (service manual and multimeter help you find the right wire - and do yourself a favour and do a good job of your connector, otherwise you might find your bike shuts down in the middle of a passing move!

(Actually just remembered the relay is now via a manual switch as well, after my automatic circuit died (it was installed around 2006) - haven't had the bike running for over a year (soon baby, soon; we'll travel the roads again soon, I promise!) so had forgotten I'd modified that till I could get a replacement)

I also have a "lighter socket" that can of course take other phone chargers, air compressors etc. That's off a separate line from the battery with it's own fuse. And of course a charging socket should I actually have a need to plug one in.

Still reading? Well.. For one other thing to think of. I used to have a relay across the oil light, so that if the oil light was switched ON (engine stopped) then this relay would cut power to the second relay cutting power to the electronics. A simple system with the idea that when I turned the bike on before starting, or if I walked away from the bike while it was warming up and it stopped, then the extras wouldn't kill the battery. It had a couple of design flaws however, 1) cranking for starting provided plenty enough oil pressure (turning on the extras while you still wanted them off) and 2) at idle the bike generates little more than enough power to run itself, at lights that can take 5 minutes or more to change could drain enough from the battery to kill your bike's ignition system - and at that level of drain you won't restart! (happened to me at lights on an uphill slope, before I had the display and automatic circuit - NOT fun!)

The box for the clock was just a sheet of metal cut and folded to shape, welded in the corners (the welding giving a place to tap threads for the screws) and a sheet of perspex (that needs replacing now) fitted over top, with some liquid gasket to seal it down. Oh, and a couple of strips that fit under the handlebar clamps to hold it in place (small mod to the clamps so they'd still hold the bars)

Sorry, been a bit rambling this post - number of interruptions to my train of thought. Hope it helps inspire someone anyway.

So i put the new battery in. I tested the voltage it was right around 12 v. With the bike running even up at 4K rpm it was only reading 12.3 v at the battery. Does this seem like a stator problem? Possible something else?

First thing is to be sure you're measuring right - I've had spent hours hunting a fault which turned out to be in my multi meter! Some of the displays aren't always so accurate either.

Second, were you measuring it at idle with all your lights etc on? At idle your bike won't be generating much power, you'd need to be at 2K RPM on many bikes (varies) to get a standard voltage with lights on (my 86 doesn't have a light switch) [edit missed your saying it was at 4K rpm]

If your meter is right and you're measuring at the battery, lights off etc, then you seem to have an issue. First thing to check is the wonderful 3 wire connection between your stator and your loom (usually 3 yellow wires coming out of the engine). The connector commonly cooks, and a lot of riders I know actually solder those wires together. Basically once one terminal loses it's connection the other two wires take up the slack, meaning they get hotter, meaning they cook. If any of those terminals look like they're discoloured, grab your soldering iron (note to yanks it's pronounced SOLDer not SODDDER! ), cut away the plugs and solder the wires together. It should not matter which goes to which but consult your manual's wiring circuit just to be sure (I can take a look if needed).

From there, well, a service manual has tips on checking that. Most of them aren't hard to follow if you have some electrical skills, if not then ask here and I'm sure some of us can guide you through it (while we also give you a bit of training on forum arguing as well )

HTH and if not, ask.

Last edited by KiwiRider; 11-25-2017 at 01:34 AM.
Reason: Duh. Should read.

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